Olefin-polysulphtde plastic



Reissued June 12, 1934 UNITED STATES 19,201 OLEFIN-POLYSULPHIDE PLASTIC Joseph 0. Patrick. Trenton, N. J.

" PATENT OFFICE};

No Drawing. Original no. 1,950,744, dated March 18, 1934, Serial No. 393,830, September 19, 1929. Application for reissue April 17, 1934, Serial No.

26 Claims. (Cl. 260-8) The present invention relates to improvements in olefin-polysulphide plastics and more particularly in the type of plastic described in my prior application 239,808, filed December 13, 1927.

Inaccordance with the present invention, I am the present invention, I am able to secure the olefin-polysulphide plastic, and particularly the soft-type plastic above referred to, 'in the form of an aqueous dispersion or latex, which can be readily purified, and from which the plastic material may be coagulated, either with or without the previous incorporation into the latex of desired compounding or stabilizing constituents. In addition, by securing the plastic material in a dispersed condition as a latex, I am enabled to coat or impregnate fabrics, textiles and various absorbent and non-absorbent bodies with the latex and subsequently cause the coagulation in situ of the desired plastic b'odies.

In carrying out the present invention, I cause the plastic or reaction body to be formed in the presence of a suitable dispersing agent, while maintaining a hydroxyl ion concentration equal to or greater than that existing in a saturated solution of freshly precipitated magnesium hydroxide. As suitable dispersing agents, I may employ precipitated magnesium hydroxide, or aqueous dispersions of peptized starch, gelatin, glue, blood-albumen, egg-albumen, or the like. In general I prefer to employ freshly precipitated magnesium hydroxide in carrying out the reac-. tion.

As pointed out in my prior application above referred to, the plastic material may be produced by reaction between an olefin-dihalide and a water-soluble polysulphide having the desired sulphur content. the reaction being quantitative.

Ordinarily an excess of one of the reaction constituents is desired, and since the polysulphide is the least expensive reagent, it is preferred that there be 'an excess of the polysulphide present. The polysulphide employed may be previously stabilized by heating for a period such that homogeneity is secured, as set forth in my prior application 369,912, filed June 10,1929, and the conditions of reaction, particularly as to temperature, may be controlled by the addition of alcohols as disclosed in said application. Thus, when used, the proportion of alcohol may vary from 10 to 80% by volume. Where such control isnot desired, the alcohol may be omitted.

The invention may beillustrated by the following examples:

21. An aqueous solution of calcium polysulphide is prepared, having a density of 31 B.,

the empirical formula of which is, by analysis,

Gas. Magnesium hydroxide is formed in this solution, preferably by the addition of a solution of sodium hydroxide, followed by a solution of magnesium chloride or sulphate, or other suitablecompound. The amount of magnesium hydroxide may vary within quite wide limits say from 2 to 50 grams per thousand cubic centimeters of the polysulphide solution. Preferably from 5 to 10 grams per liter provides a desirable form of latex-like dispersion product best adapted for handling. Thus, to each 1000 cubic centimeters of the above calcium polysulphide solution, there may be added 50 cubic centimeters of a solution containing 290 grams sodium hydroxide per liter and 100 cubic centimeters of a solution of magnesium'chloride containing the chemical equivalent of 105 grams of magnesium hydroxide per liter, these proportions providing a slight excess of sodium hy'- droxide. A semi-gelatinous dispersion of mag- 85 nesium hydroxide, the proportion of dihalide added being very slightly less than the equivalent required for reaction. Thus, with the solution above described, 157 cubic centimeters of ethylene dichloride per liter of original calcium polysul-- phide solution is used. 'To avoid excessive heatv ing, the olefln-dihalide i., added in small portions with vigorous agitation. If desired, the polysulphide solution may first be slightly warmed, say to 80 to 100 F., to accelerate the beginning of the reaction. The addition of ethylene dichloride is controlled so that the temperature does not rise excessively, say to above to F. After the dihalide has been completely added, the reaction may be completed by further warming the mixture to, say, 1'75 to F. for a short period, until 110 or the final 75 as here- 90 phide plastic forms in thisreaction mixture as a fluid dispersion, latex-like in character, which settles out of' the reaction mixture. The supernatant solution may be removed by decantation and the latex-like. dispersion may be readily washed with water and settled, the .wash water being decanted. This is repeated until the soluble salts and other undesirable constituents presentare completely removed. This'latex may then be coagulated or compounded and coagulated, as

I suitably in the same proportions as set forth in connection with the first example above. The

\ mixture is then heated to 120 F., and slightly less than equivalent quantity of ethylene dichloride is added in small portions at a time with vigorous agitation, while holding the temperature of the mixture below about 175 F. The amount of ethylene dichloride so added is about 208 grams per liter of the original polysulphide solution. The latex of olefin-polysulphide plastic forms and is settled and separated from the other products of reaction by decantation or centrifuging, thoroughly washed as in the first example and is then reachr forcoagulating or compounding and coagulating.

.The latex-like dispersion of the olefin-polysulphide plastic produced in accordance with the method of the present invention may be coagulated by acidifying it with any suitable acid, such as hydrochloride or sulphuric acid, or organic acids such as acetic'acid, formic acid, or the like; and on acidulation, the. olefin-polysulphide plastic coagulates to form an elastic, spongy mass, from yellow to white or nearly white in color. The coagulum has the characteristics of the soft plastic described in my prior applications above referred to, being pliable and resembling in appearance soft vulcanized rubber. Its characteristics may be improved by incorporating into it, suitably on a rubber mill, any desirable proportion of a metallic oxide such as litharge, zinc oxide, magnesium oxide or other compounds of the class of sulphur carriers well known in the rubber industry. Various inert materials, such as those of the type used in compounding rubber, for example. fibers, wood flour, carbon black, glue, asbestos. and the like, may be compounded with the latex'either with or without the sulphur carrier. The compoundmay then be suitably heated to effect its stabilization, the time of heating varying with the temperature employed. Temperatures from C. upwards may be used. Thus, by heating in autoclave under 40 lbs. steam pressure for 40 minutes to 1 hour, a completely stable and homogeneous product may be secured. Instead of first coagulating the latex and incorporating a sulphur carrier and other compounding ingredicuts into the coagulum, such materials may be incorporated in the latexbefore coagulation.- Thus, from 1 to 10% of litharge or zinc oxide may be thoroughly mixed with a thick latex, the mix-- ture then heated (as it does not undergo 008-81118- foon'iplete disappearance of'the olefln-dih'alide is indicated by loss of its odor. The olefin-polysultion on heating) imder the same conditions as set forth in connection with the compound above, and the heated and stabilized mixture then coagu- 'lated. Other compounding ingredients maybe in- The resulting product has the characteristics of' a soft unvulcanized rubber, does not flow under pressure, is notseparable by organic solvents; it is not aifected or swelled by organic rubber solvents, including carbon disulphide, and has dielectric qualities superior to those of rubber. Furthermore, it completely resists the action of oils, salt water and the like, and has an extremely low power loss when used as a dielectric.

The latex of the olefln-polysulflde plastic is stable and may be preserved and stored as such, or may be treated with a sulphur carrier,- as hereinbefore set forth, and the stabilized latex preserved and stored for further use. If the latex is stored for periods of a week or more, it may undergo a change somewhat analogous to polymerization. The addition of an acid then produces the subsidence of'a granular product from the liquid. The latex can,'however, be restored to its original condition by subjecting the dispersion; before adding the acid, to temperatures around the boiling point of water for a few minutes, the addition of the proper amount of acid will then produce the. massive coagulum.

The present method of operation is particularly desirable in the manufacture of the soft-type of olefin-polysulphide plastic and those approaching the soft-type;that is, corresponding to the polysulphides of the formula R8: to RS and upwards. It may also be employed in the production of olefin-polysulphide plastics of lower sulphur content in securing dispersed products but as the proportions of sulphur decrease, the resmlting product loses its latex-like character and assumes a more granular, pulverulent character, as in the process described in my prior application Serial 3 mixtures of olefins such as are secured by the;

formation of unsaturated hydrocarbon gases derived from pressure cracking processes, natural gas-cracking processes, and the like. Furthermore, as also disclosed in my prior applications, a

wide range of soluble polysulphides may be employed in securing the reaction products.

I claim:

1. The method of producing an olefln-polysul phide plastic in dispersed form,-'which comprises reacting upon an olefln-dihalide with a solution of a water soluble polysulphide in the presence of a dispersing agent from the group including magnesium hydroxide and dispersions of peptized. starch, gelatin, glue, blood-albumen, egg albumen and the like while maintaining an alkalinity at of freshly precipitated magnesium hydroxide.

2. The method of producing an organic polysul- 1 least equal to that existing in a saturated solution ethylene dihalide with a solution of a water soluble polysulphide in the presence of magnesium hydroxide, thereby forming alatex-like dispersion of an organic polysulphide body.

4. The method of producing an organic polysulphide plastic which comprises reacting upon a mixture of dihalides of gaseous olefin hydrocarbons with a solution 'of a water-soluble polysulphide in the presence of magnesium hydroxide, thereby forming a latex-like dispersion of an organic polysulphide body.

5. The method of forming a soft olefin-polysulphide plastic in latex-like dispersion which comprises reacting upon an olefln-dihalide with an aqueous solution of a polysulphide having a formula RSn, wherein n is at least 3 and R is the equivalent of two monovalent positive'radicals in the presence of a dispersing agent from the group including magnesium hydroxide and dispersions of peptized starch, gelatin, glue, blood-albumen, egg albumen and the like, while maintaining a hydroxyl ion concentration at least equal to that existing in freshly precipitated magnesium hydroxide.

6. The method of producing a soft olefln-poly sulphide plastic in latex-like dispersion wherein an olefin-dihalide is reacted upon with an aqueous solution of a polysulphide of formula RS wherein n is at least 3 and R is the equivalent of two monovalent positive radicals in the presence of freshly precipitated magnesium hydroxide.

'7. The method of forming a soft olefin-polysulphide plastic in the form of a latex-like dispersion, which comprises incorporating a dispersing agent from the group including magnesium hydroxide and dispersions of peptized starch, gelatin, glue, blood-albumen, egg-albumen and the like into an aqueous solution of a polysulphide of formula RSn wherein n is 3 or higher and R is the equivalent of two monovalent positive radicals, and admixing an ol eiin-dihalide with said solution.

8. The method of producing a soft olefin-polysulphide plastic in latex-like dispersion, which comprises dispersing magnesium hydroxide in an aqueous solution of a polysulphide of formula RS wherein n is at least 3 and Ris the equivalent of iwo monovalent positive radicals, admixing an olefln-dihalide therewith and warming to cause reaction therebetween, whereby a latex-like dispersion of a soft olefin-polysulphide plastic is secured.

9. The method of producing a soft olefin-polysulphide plastic, which comprises forming dispersed magnesium hydroxide in an aqueous solution of a polysulphide of formula R Sn, wherein n is at least 3 and R is the equivalent of two monovalent positive radicals, and adding an olefin-dihalide thereto, whereby the olefin-polysulphide plastic is formed in latex-like dispersion.

10. The method of producing a soft olefin-polysulphide plastic which comprises reacting upon a polysulphide containing a proportion of sulfur adapted to produce a soft-type plastic, while in aqueous solution, with an olefln-dihalide in the impurities from said latex, and coagulating the latex.

11. The method of producing a soft-type olefinpolysulphide plastic which comprises incorporating a suitable dispersing agent from the group including magnesium hydroxide and dispersions of peptized starch, gelatin, glue, blood-albumen, egg albumen and the like in an aqueous solution of a polysulphide of the general formula RS, wherein n is at least 3 and R is the equivalent of two monovalent positive radicals, reacting thereupon with an olefln-dihalide, thereby forming a latex-like dispersion of the olefin polysulphide plastic, washing said latex to remove soluble impurities therefrom and acidifying the latex, thereby causing coagulation of the plastic.

12. The 'method of producing an olefin-polysulphide plastic, which comprises reacting with an olefln-dihalideupon a polysulphide of formula 'RSn, wherein n is at least 3 and R is the equivalent of two monovalent positive radicals, in aqueous solution, in the presence of a dispersing agent from the group including magnesium. hydroxide and dispersions of peptized starch, gelatin, glue, blood albumen, egg albumen, and the like while maintaining an alkalinity at least equal to that existing in a saturated solution of freshly precipitated magnesium hydroxide, thereby forming a latex-like dispersion of an olefin-polysulphide plastic, washing said latex and acidulating the washed latex, thereby precipitating the olefin polysulphide plastic.

13. The method of forming a soft-type olefinpolysulphide plastic, which comprises reacting with an olefln-dihalide upon an aqueous solution of a polysulphide of formula RSn, wherein n is at least 3 and R is the equivalent of two monovalent positive radicals, in the presence of a solution of freshly precipitated magnesium hydroxide, thereby forming a latex-like dispersion of the plastic, separating and washing said latex, and acidulating the latex, thereby coagulating the plastic.

14. A latex-like dispersion of a soft-type olefinpolysulphide plastic, the type formula of the olefin being CnHhi. r

15. A latex-like dispersion of an olefin-polysulphide plastic having a sulphur content corresponding to a polysulphide of the formula. RSn. wherein n is at least 3 and R is the equivalent of two monovalent positive radicals.

16. A latex-like dispersion of an organic polysulphide derivative produced by theaction of an olefin dihalide on a water soluble polysulphide of the formula RSn, wherein n is at least 3 and R is the equivalent of'two monovalent positive radicals. said dispersion containing precipitated magnesium hydroxide as the dispersing agent.

17. A, latex-like dispersion of an organic poly-. sulphide derivative produced by the action of ethylene dihalide .ona water-soluble polysulphide of the formula RS1, wherein n is at least 3 and R is the equivalent of two monovalent positive radicals, said dispersion containing precipitated.

taining precipitated magnesium hydroxide as the dispersing agent.

an ethylene- 19. A latex-like dispersion of polysulphide havinga sulphur content corresponding to a polysulphide of the formula R811,

wherein n is at least 3 and R is the equivalent of two monovalent positive radicals.

20. A latex-like dispersion of an organic polysulphide plastic produced by the action of a mixture oi dihalides oi gaseous oieiins on a water I soluble polysulphide oithe formula R811. wherein n is at least 3 and R is the equivalent of two monovalent positive radicals.

21. A composition comprising an admixture 01 a latex-like dispersion of a soft-type olefin-pol sulphide plastic and compounding ingredients.

22. A composition comprising an intermixture of a latex-like dispersion of a soft-type olefin-r polysulphide plastic and a sulphur carrier.

23. A composition comprising an intermixture 01 a latex-like dispersion of a soft-type olefinpolysulphide plastic and a sulphur carrier, said composition being stabilized by heat.

24. A composition comprising an intermi'xture of a latex-like dispersion of a soft-type olefinpolysulphide plastic andlitharge.

25. A composition comprising an intermixture of a latex-like dispersion of an olefln-polysulphide plastic and litharge. said composition being stabilized by heat.

26. A composition comprising an intermixture of a latex-like dispersion of a soft-type olefinpolysulphide plastic, inert material, and a suiphur carrier.

JOSEPH c. PATRICK. 

